Flow motion of air inducted into an intake manifold may be modified to promote mixing of air and injected fuel in a combustion chamber of a vehicle engine to improve combustion efficiency. Air flow in the intake manifold may be modified by redirecting the flow in a particular direction to increase air flow velocity prior to entry into the combustion chamber. The increased air flow velocity may homogenize the air-fuel mixture in the combustion chamber, and may speed up propagation of an ignition front through the combustion chamber. The homogenous air-fuel mixture may combust with improved efficiency to reduce fuel emissions. The increased propagation speed of the ignition front may allow longer interaction of air with injected fuel, and may promote rapid combustion of the air-fuel mixture to produce thermal energy required for piston motion.
A charge motion control valve may be used in an engine to induce swirl motion or turbulent flow by blocking a portion of an inlet of a flow passage, and redirecting air flow in a particular direction within the flow passage. The air may be further flowed to the combustion chamber where air mixes with injected fuel. By closing the portion of the passage inlet to redirect air flow, flow velocities of air inducted into the combustion chamber may increase to promote adequate mixing of air and injected fuel prior to ignition of the air-fuel mixture.
An example charge motion control valve is disclosed by Magnan in U.S. Pat. No. 8,056,534. Therein, the charge motion control valve includes a valve plate mounted within an inlet passage of an engine runner via a control shaft driven by an electric or vacuum motor. Further, a sealing member is secured to an outer face of the engine runner to reduce air leakages between the engine runner and engine.
However, the inventors have recognized potential issues with such a charge motion control valve design. For example, the valve plate may be mounted within the inlet passage in such a manner that the plate may not completely block side openings at the periphery of the passage inlet, which may cause air leakage and reduce combustion efficiency of ignited fuel in the combustion chamber. Alternatively, use of seals may add unwanted friction and further may create issues upon degradation of the seal over time.
The inventors herein have developed a charge motion control valve to address some of the issues noted above. In one example, a charge motion control valve comprises a valve plate with a pivot axis mounted in a body coupled to a manifold runner, the plate having a rear portion overhanging the pivot; and a first sealing surface in the manifold runner to receive a surface of the rear portion of the valve plate when fully opened; and a second sealing surface in the body to receive an opposite surface of the rear portion of the valve plate when fully closed. In this example, the valve plate is fully open when the plate is adjusted to a fully unblocked position within a flow passage formed in the manifold runner and body. Further, the valve plate is fully closed when the plate is adjusted to a fully blocked position within the flow passage. Alternatively, a shell membrane may be placed in face-sharing contact with a portion of the valve plate at the passage inlet.
In this way, the rear overhang on the valve plate may reduce air leakages through a back end of the valve plate, and the shell membrane may minimize air leakages at the periphery of the passage inlet. By reducing air leakages around the periphery of the passage inlet, flow motion of air inducted into the flow passage may be redirected to a particular segment of an intake valve in the combustion chamber to maximize swirl which may promote adequate mixing of air and injected fuel to improve combustion efficiency.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.